A differential pressure transmitter generally operates by providing two pressure values to a sensor. The sensor converts a difference between the two pressure values into an electrical signal, which can then undergo additional signal processing. To achieve optimum sensitivity, the sensor may operate near a differential pressure that can cause failure of the sensor. To avoid damage to the sensor, an overpressure mechanism can be employed to limit the differential pressure that is input to the sensor.
While various overpressure protection mechanisms exist, some of these mechanisms lead to the generation of small errors in the differential pressure measurements that are output from a pressure sensor. Others of these mechanisms are costly to implement due to expensive machining operations. In addition, some of these mechanisms are simply unreliable under specific operating conditions and can still allow sensor damage to occur.